Computer Sciences > GATE 2024 Set-2 > Networking
Node X has a TCP connection open to node Y. The packets from X to Y go through an intermediate IP router R. Ethernet switch S is the first switch on the network path between X and R. Consider a packet sent from X to Y over this connection.
Which of the following statements is/are TRUE about the destination IP and MAC addresses on this packet at the time it leaves X?
A
The destination IP address is the IP address of R
B
The destination IP address is the IP address of Y
C
The destination MAC address is the MAC address of R
D
The destination MAC address is the MAC address of S

Correct : b,c

To determine the correct destination IP and MAC addresses when a packet leaves Node X, let us analyze how addressing works across different layers of the OSI model as data moves through an internetwork.
1. Destination IP Address Analysis (Network Layer - Layer 3): • IP addresses are used for end-to-end routing across different logical networks.
• The source IP address is always the original sender (Node X), and the destination IP address is always the ultimate recipient (Node Y).
• Intermediate devices like routers (R) or switches (S) do not change the ultimate destination IP address of a standard data packet during transit.
    → Therefore, the destination IP address is the IP address of Y. (Validates Option b)
2. Destination MAC Address Analysis (Data Link Layer - Layer 2): • MAC addresses are used for hop-by-hop delivery within the same physical local area network (LAN) segment.
• Node X uses its routing table to determine that Node Y is on a different network, meaning the packet must be sent to its default gateway, which is the intermediate IP router R.
• Node X uses ARP (Address Resolution Protocol) to find the MAC address matching Router R's IP address and sets it as the destination MAC address.
What about Ethernet Switch S? An Ethernet switch is a Layer 2 device that transparently forwards frames within a local network segment using its MAC address table. Packets are never logically addressed to the switch itself unless the switch is the final management destination.
    → Therefore, the destination MAC address is the MAC address of the next-hop router R. (Validates Option c)
Conclusion: Statements b and c are both correct.

Similar Questions

In an Ethernet local area network, which one of the following statements is TRUE ?
#99 MCQ
Consider a network connecting two systems located 8000 kilometers apart. The bandwidth of the network is 500 × 106 bits per second. The propagation speed of the...
#521 Fill in the Blanks
Which of the following fields is/are modified in the IP header of a packet going out of a network address translation (NAT) device from an internal network to a...
#867 MSQ

Related Topics

No tags found

Unique Visitor Count

Total Unique Visitors

Loading......